Purpose: Host modulatory therapy has been proposed as a treatment for periodontal diseases. A class of herbal medicines, known to be immunomodulators, alters the activity of immune function through the regulation of informational molecules such as cytokines. In the current study, we tested the hypothesis that herbal immunomodulator drugs act as an adjuvant to scaling and root planing (SRP) in alleviating periodontal inflammation by improving clinical and biochemical parameters. Methods: Sixty healthy subjects (30 in each group) with moderate and severe chronic periodontitis were enrolled in a double-blind, placebo-controlled, double-masked randomised controlled trial. The control group was treated with SRP and a placebo, whereas the test group was treated with SRP followed by dietary supplementation of Septilin for 3 weeks. Periodontal clinical parameters and serum C-reactive protein (CRP) levels were evaluated for all patients at the baseline, 3 weeks, and 6 weeks. Results: Improved gingival index scores found in the test group as compared to the control group were found to be statistically significant only after 3 weeks (P<0.001). In contrast, the decrease in the sulcus bleeding index and pocket depth scores was statistically highly significant in the test group as compared to the control group after 3 weeks and 6 weeks (P<0.001). However, reduced clinical attachment level and CRP scores, as reflected in the test group as compared to the control group, were not found to be statistically significant after both 3 weeks (P>0.05) and 6 weeks (P>0.05). Conclusions: The results of this clinical-biochemical study suggest that dietary supplementation with herbal immunomodulatory agents may be a promising adjunct to SRP and may aid in improving periodontal treatment outcomes.